This application requests support for the Nutrition Coordinating Center (NCC) at the University of Minnesota, as a national research resource. NCC develops, provides, and supports state-of-the-art methods and databases related to the collection and analysis of dietary data in studies of diet and health. NCC has the most comprehensive and detailed food and nutrient database appropriate for research purposes. Methodologies, quality control, and training are of the highest quality required for research. The stature of NCC personnel, activities, software, databases, and support services is documented with listings of studies supported, client investigators, letters of support from investigators nationally, and 450 references from the scientific literature that have used NCC methods and databases in their research. Three aims are proposed. Activities for Aim 1 will maintain and update the NCC database of 18,000 foods and 108 nutrients associated with a new interactive, computer-based software system (NDS-R 4.0) to collect, code, and analyze dietary data to generate nutrients consumed. Five additional nutrient fields will be added to the database, and updated versions of the database will be released to clients approximately every nine months so rapid changes in the nation's food supply can be represented. Activities for Aim 2 will enhance the new NDS-R software, and in-house computer programs to maintain the database, to further improve flexibility and save data processing time. Two revised versions of the interview system will be developed and released to clients. Activities for Aim 3 will design, produce, and validate a new methodology and software tool to enable investigators to modify existing food-frequency focused on a certain nutrient. An example of the methodology will be developed for trans fatty acids and validated on a sample of healthy adults. The proposed work will allow NCC to continue to support biomedical research nationally, it will provide continuity and comparability for ongoing and future studies, and it will help control costs to investigators for providing software, databases, and diet-related research services.